Electric motor controller



Aug.. 18,- 1931.

R., G. LOCKETTT ELECTRIC MC'IOR GONTRLLER 2 Sheets-Sheet Filed Nov. 7 1928 ATTORNEY Patented Aug. 18, 1931 UNITED s'rA'rEs;

PATENT OFFICE RALPH G. Locxm, OI WAUWA'I'OSA, WISCONSIN, ASBIGNOB, BY mm: ASSIGHIENTS, TO OUTLEB- INC, A CORPORATION OI DELAWARE merino xoron ooxraomna Application M Iovember 7. 192:. Serial no. 317,106.

This invention relates to improvements in electric motor controllers, and more articularly to semi-automatic controllers or electric motor driven washing machines and the like.

An object of the invention is to rovide extremel. simple and eflicient contro means ted ,or brought into register wit the oor or ,doors of the outer casing or tub.

Another object is to provide means, in cluding means providing a dynamic braking effect to facilitate stopping of the controlled motor and the machine being driven thereby.

Another object is to provide means for simultaneously subjecting the motor to the action of the aforementioned means providing a dynamic braking effect and to the action of electromagnetically controlled mechanical braking means for insuring quick sto pin thereof under all conditions.

not er object is to provide means subject to initial manual control for effecting automatic control of the starting, accelerating, running, plugging and reversing connections of the controlled motor.

Another object is to rovide additional manual control means a apted upon initial stopping of the motor to commutate the circuit connections of the latter for insuring unidirectional operation thereof at a predetermined fixedspeed during inching.

Other objects and advantages vention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the invention which will now be described, but it will be apparent that the embodiment illustrated is susceptible of modification in the details thereof without departing from'the scope of the appended claims. y

In the drawings, Figure 1 is a schematic and diagrammatic view of a motor driven of the "inwashing machine and the control means therefor, and

Fig. 2 is an across-tlie-line diagram of the circuits and connections illustrated in Fig. 1.

In the drawings (referring first to Fig. 1) the reference character W designates in general a power operated washing machine of a known t e to the control of which the means herein described are particularly adapted. Said washing machine may comprise an inner cylinder or container 5 the interior of which is divided into aplurality of compartments or pockets 6, 7 and 8, as shown; each compartment being provided with a hip ed or otherwise movable cover or door 6 and 8, respectively.

Said cylinder is rotatably supported within a ,stationa tub or casing 9, the latter having a slida 1e or otherwise movable door or cover 9', which is preferably ada ted when in the closed position illustrate to render the casing 9 watertight and ada' ted when opened (as shown in dotted lines to provide access to the cylinder 5. The washmg machine may be provided with a suitab e base or support, as indicated in dotted lines at 10.

The cylinder 5 is connected by means of suitable gearing 11, 12 and shaft 13, with the armature a of a compound wound motor M to be driven by the latter, the series field of said motor being shown at sf and the shunt field thereof being shown at 871. It is to be understood, however, .that any other suitable type of motor may be employed if desired.

The cover 9 of easing 9 is provided with a contactor 14 which is adapted in the closed position of the door to bridge contacts 14" or initiating the automatic operation of motor M,' as hereinafter" more fully described; and upon opening of .cover 9 the contacts 14, 14 are separated to interrupt such automatic operation. A V

Also upon full open positioning of cover 9 the contact 15 carried thereby is adapted to bridge contacts 15 to provide for control of motor M through inch push button 16. The cooperative relationship of the contacts 14, 14" and 15, 15 with respect to door 9 is merely shown diagrammatically, and any other suitable arrangement may be employed for securing the functions desired. Motor M is adapted to be supplied with current from a suitable source of supply indicated at lines L L subject to control by an electromagnetically operable single pole main switch 17, an electromagnetically operable double pole switch 18, a lockout switch 19, and a reversing and accelerating drum illustrated diagrammatically at D; assuming closure of the two-position snap switch 20 through depression of On push button 20 and assuming closure of contacts 14, 1 1 through closure of door 9 of casing 9.

Drum D as shown is adapted to be continuously driven unidirectionally by a pilot motor M through the medium of suitable gearing 21; said motor 1 1 being directly connected to lines L L by conductors 22 and 23. Said drum D comprises a set of stationary contacts 24: to 32, inclusive, and sets of movable contact segments 24*, 25 27, 28 30 31 32 and 24: 26*, 27 329 30", 31 32". Main switch 17 is provided with normally open main contacts 17, and normally open auxiliary contacts 17. Switch 18 is provided with normally open main contacts 18 and 18", normally closed main contacts 18, and normally open auxiliary contacts 18, 18 and 18*. Switch 19 is of a known form comprising normally open contacts 19, a

' shunt operating coil 19*, and a series lockout coil 19 which acts in the usual manner upon the armature 19 to initially hold the contacts 19- in open position.

The aforedescribed elements provide for starting, accelerating, running, plugging and reversing control of the driving motor M, the commutation of resistance sections R R R and R being cont-rolled by drum D in the manner hereinafter set forth. Also as will be apparent, upon closure of auxiliary contacts 18 and 18 of switch 18 the brake coil B is energized to effect release of the brake.

In order to efiect an initial stop of motor M it is only necessary to lift the cover or door 9 of tub 9 sufficiently far to effect opening of contacts 14?, thereby interrupting the energizing circuit of the winding of switch 18 and the circuit of the coil 19 of switch a closed loop, including the resistance 1' is provided for the armature a of motor M, which causes a dynamic braking effect to assist the brake B in bringing said motor to rest as hereinafter more fully described.

Upon full open positioning of the cover 9* of tub 9 the contacts 15 are bridged by contact 15, to provide for energization of the operating winding of a switch 33 upon closure of inching push button switch 16; said switch 33 being provided with normally open main contacts 33 and 33 and normally open auxiliary contacts 33, 33 and 33 The contacts 33 and 33* are adapted upon closure thereof to connect the motor armature to the line through suitable resistance T the resistance 7 being connected in series with said resistance 1' and in shunt to the motor armature due to closure of contacts 18 of switch 18, as aforcdescribed.

Closure of the auxiliary contacts 33 and 33 of switch 33 likewise provides for energization of the coil of brake B to release the latter, and closure of auxiliary contacts 33 and 33 of switch 33 completes the energizing circuit of the winding of main switch 17 with consequent closure of the main contacts 17 of the latter. The motor thereupon operates unidirectionally at a predetermined relatively slow speed for inching, so long as the push button switch 16 is held closed.

Inasmuch as the door 9 of tub 9 is open during the aforementioned inching opera tion, it is obvious that the operator may readily judge, from the relative rotary position of the cylinder 5, the time at which to release the push button switch 16 in order to bring the motor to a stop with any one of the doors 6, 7 or 8 in the desired registering relation to the openingl) in the tub or casing 9.

In Fig. 1 the compartment 6 is shown in proper registration with opening 9 for unloading of said compartment; that is to say, the lower partition 6 is in a position to facilitate unloading of the material from said compartment through the opening 9 upon opening of the compartment door. Each of the other compartments 7 and 8 may thereafter be brought in sequence into unloading position by pro er control of motor M through said pus button switch 16. Then all of the compartments have been unloaded they may be brought in sequence to loading position, as indicated by way of example in dotted lines at 6".

If during the inching or spotting operation one of the compartment doors is allowed to pass beyond its proper registering position for unloading or loading, the operator may proceed to bring the next succeeding compartment door into registry; so that the first mentioned compartment door may be spotted when the inching cycle of unloading or loading has been otherwise completed; or the operator may hold the ush button switch 16 closed until a substantially complete revolution of the cylinder is efto washing machines having single compartment or plural compartment cylinders;

20, contacts 14, -14 of the rim door switch,

and to washing machines of this type where in it may be desired to stop the cylinder with the respective compartment doors in the same angular position for both unloading and loading.

The shunt field shf is preferably provided with the usual field discharge resistance r and a protective resistance r ispreferably included in circuit in series with the brake coil-B.

Operation of the controller will now be described with particular reference to the diagram of Fig. 2. Thus, assuming closure of the switch 20 by depression of the push button 20, the other parts of the device being in the respective positions illustrated, an energizing circuit is completed for the operating winding of switch 18, said circuit extending from line L through said switch and through said winding 18 to line L. Energization of said switch 18 effects closure of its main contacts 18*, 18 and opening .of its normally closed main contacts 18.

Auxiliary contacts '18, 18 and 18 of switch 18 are also closed; closure of contacts 18 and 18 effecting energization of the coil B of the brake to release the latter, said circuit extending from line L through switch 20, thence through said coil B andprotective resistance. r, and

I through contacts 18 and 18 to line L Closure of said contacts 18 and 18 effects energization of the operating winding of main switch 17 the energizing circuit thereof extending from line L through switch 20, thence through said winding 17 and con; tacts 18 and 18 to line L This results in closure of 'main contacts 17* and auxiliary contacts 17 of switch 17.

As aforestated the drum D isrotated unidirectionally at a predetermined relatively slow speed by means of the pilot motor M which is shown as connected to lines L, E

through conductors 22, 23, respectively. For

purposes of description it may be assumed that the'drum is first brought into a position to effect engagement of its segments 24: 25, 27 and 28 with its contacts 24, 25, 27 and 28, respectively. This completes a circuit for the driving motor M for effecting operation of the latter in one direction.

Said circuit may be traced from line L through the series lockout coil 19 of switch 19, thence through the step of resistance R to contact 27 and segment 27", to segment,

28" and contact 28, contacts 18' through the armature of motor M from left to right, contacts 18 to contact 25 and. segment 25, to segment 24! and contact 24, and through the series field sf and contacts 17 to line L. Closure of contacts 17 of main switch 17 likewise completes an energizing circuit for the shunt field shf, said circuit being obvious.

Closure of auxiliary contacts 17 of main switch 17 eflects completion of an energizing circuit for the shunt operating coil 19 of switch 19, said circuit extending from line L. through switch '20, contacts 14, 14 of the run? door switch, through said coil 19 and contacts 17 to line L Energize.- tion of said coil 19" tends to effect immediate closure of contacts 19 of switch but due to energization of the series coil 19 in the manner aforedescribed said contacts 19 are held in open position pending a decrease to a predetermined value of the current travsistance section R is connected in circuit in arallel with the resistancev section R wit consequent acceleration of motor M, The coils 19 and 19 of switch 19 are preferably so calibrated as to provide for closure of contacts 19 upon a predetermined degree of acceleration of motor M after inclusion of resistance R in circuit. As a result of this operation resistance R is ini cluded in circuit in a'rallel with each of the resistances R and 1?. v

Continued rotation of drum D results in engagement of segment 31 with contact 31, with resultant inclusion of resistance R in circuit in parallel with each of the resistances R R and R to further accelerate motor M; and thereafter vupon engagement of segment 32* with contact 32 the coil 19' of switch 19 andall of the resistances R R QR and R are short-circuited to provide for connection of motor M directly across the line.

After full speed operation of motor M for .a predetermined period of time the armature circuit connections are interrupted by simultaneous disengagement of segments 24" 25, 27, 28, and 32 from their cooperating contacts,-the segments 30? and 31 having been previously disenga d from their cooperating contacts, as will be ob-. vious.

4 Upon continued rotation of drum D segments 24 26 27 and 29 are simultane- -ously brought into engagement with their cooperating contacts 24, 26, 27 and 29, respectively; thereby providing plugging and reversing circuit connections or motor 'M,

which circuit may be traced from line L through the series lockout coil 19 of switch 19 and through resistance R to contact 27 and segment 27 to segment 29 and contact 29, by contacts 18 of switch 18 through the armature of motor M from right to left, thence through contacts 18 to contact 26 and segment 26, to segment 24 and contact 24, and through the series field sf and contacts 17 to line L As will be apparent from the foregoing description the plugging and reversing connections for motor M are provided solely through the operation of drum D,-the switches 17 18 and 19 remaining in closed position. Upon engagement of segment30 with contact 30, due to continued rotation of the drum, resistance sections R and R will be simultaneously connected in the armature circuit in parallel with each other and in parallel with resistance section R Thereafter the segment 31 is brought into engagement with contact 31 to effect connection of resistance R in circuit in parallel with each of the resistances R R and R and continued rotation of drum D effects engagement of segment 32 with contact 32 to again connect motor M directly across the line while operating in such reverse direction.

After a predetermined period of operation of motor M in such reverse direction the drum D acts in the manner aforedescribed to interrupt the circuit and to thereafter again complete the circuit connections for operation of the motor in a forward direction, the plugging and accelerating operations being effected in the manner aforedescribed. I V

The aforedescribcd cycle of starting, accelerating, running, plugging and reversing operations is repeated automatically for the desired washing period, whereas the initial stop of motor M is effected by raising the cover 9 of the casing 9, which causes 0 enoor ing of contacts 14, 14: of the run switch. This interrupts the energizing circuit of the winding of switch 18, with consequent opening of the contacts 18- and 18 of the latter to interrupt the line connections for the motor independently of the drum D.

Switch 18 in opening likewise effects closure of its normally closed contacts 18 thereby connecting the resistance r in a closed loop including the motor armature. I have V discovered that connection of resistance r nected from the line. In this connection it v is to be observed that the shunt field discharge resistance 1' serves under such conditions to augment or modify the time constant of the gradually disappearing magnetic flux. The dynamic braking efi'ect thus provided tends to bring the motor to rest. At the same time, upon opening of the auxiliary contacts 18 and 18 of switch 18 the energizing circuit of the brake coil B is interrupted, thereby releasing the brake to further assist in stopping the motor.

Similarly, upon opening of the auxiliary contacts 18 and 18 of switch 18 the energizing circuit of the winding of switch 17 is interrupted, with consequent opening of its main contacts 17 and opening of its auxiliary contacts 17*. Upon opening of said auxiliary contacts 17 the circuit of shunt coil 19 is interrupted to permit normal open positioning of contacts 19 of switch 19.

The initial stop of motor M is thus rapidly effected without regard to the relative angular position of the compartment doors 6*, 7 or 8 with respect to the opening 9 in casing 9 at the time when the cylinder 5 is actually brought to a stop. It may happen that one of the compartment doors is in proper registering relation to the opening 9 as the result of the initial stopping operation, and assuming full open positioning of the casing door 9 the material may be unloaded from that compartment.

In most instances, however, it will be necessary to inch the motor M in order to first bring one of the compartments to proper unloading position. Assuming full open positioning of the casing door 9, the inch door switch contacts 15, 15 will be closed, thereby subjecting motor M to energization control by push button switch 16 through the medium of the double pole electromagnetically operable switch 33.

Thus upon closure of push button switch 16 an energizing circuit is completed, which circuit may be traced from line L through switch 20 and the contacts 15, 15 of the inch door switch, thence through said push button switch 16 and the winding of switch 33 to line L I Upon closure of the normally open auxiliary contacts 33 and 33 of switch 33 an energizing circuit is provided for the coil of brake B to effect release of the latter, said circuit extending from line Ltthrough switch 20 brake coil B and resistance r, and thence through said contacts 33 and 33 of switch 33 to line L Similarly upon closure of auxiliary contacts 33 and 33 of switch 33 an energizing circuit is provided for the winding of main switch 17, to effect closure of the contacts 17 of the latter; said circuit extending from line L through switch 20, thence through said coil 17 and contacts 33, 33 to line L Switches 33 and 17 being thus closed, an

uni irectional operation of motor M at a predetermined constant relatively low speed.

Said circuit may be traced from line L through resistance 5"- and contacts 33 of switch 33, thence through the armature of motor M from left to right, and through contacts 33", series field sf and contacts 17 to line L. Also due to normally closed positioning of contacts 18 of switch 18 the resistance 1- is included in the circuit in series with resistance 'r and in shunt to the armature of motor M.

The circuit connections just described are maintained pending release of push button switch 16; and inasmuch as the casing door 9 is open and the cylinder 5 is rotating at a relativel slowspeed, the operator may readily ju go the proper time at which to release the push button 16 in order to bring the first compartment into proper registering relation to opening 9 for unloading. Thus, upon release of push button switch 16 the winding of switch 33 is de-energized and the contacts 33 and 33 of the latter in o ning efiect disconnection of motor M rom the line.

At the same time opening of auxiliary contacts. 33 and 33 of switch 33 effects setting of the brake through deenergization of its coil B. Moreover, the aforedescribed closed loop including resistance 1- is provided for the motor armature due to continued closure of the contacts 18 of switch 18, and the motor is quickly brought to rest.

The prime stop or initial spotting operation having been effected in the manner just described, the registering door of the particular compartment is opened and the material removed, whereupon the oompart-' ment door is again closed (it it is the hinged or swinglng type shown, or if it is of the sliding t pe it may be latched in open position). he operator then again depresses the fpush button switch 16to efiect operation 0 motor M in the manner aforedescribed, said switch being released when the cylinder is in the proper angular position to provide for accurate unloading registration of the next succeeding compartment door when the motor is brought to a stop.

' The compartment doors are thus brought to unloading registration with the opemng 9 in proper sequence and thereafter the same may be likewise brought in s uence to loading position. When the cy inder compartments have been reloaded, the washing cycle may be again initiated by merel closing the door 9 of the casing 9, suc washing cycle havingbeen previously de-' scribed in detail.

It may be noted that due to the continuous rotation of drum D it might happen that all of the drum contacts are engaged by their respective segments at the time of c osing the casin door 9 to initiate the washing c cle. owe'ver, due to previous opening 0 switch 19 the-contacts 19" there of will be maintained in open osition for a certain period through the action of lockout coil19, so that in any event the motor can onl be initially subjected to such a value 0 current as will sistances R, R and R w en connected in arallel. The motor windings will thereore be adequately protected under all conditions.

As aforeindicated the sequence of opera tions which are subject to manual control may be varied at will by the operator. Also, as will be apparent to those skilled in this art, the device is susceptible of various other changes in the details oi construction and operation thereof.

Thus if desired an suitable timing means may be em loyed or efiecting automatic opening of t e door switch contacts 14, 14,

or of contacts connected in series with the latter.

As aforestated the pilot motor M is continuously operable, and this is desirable, since in practice it is preferred to utilize the pilot motor for driving jointly as many aseight or more of the drums D of correspon ing washer control devices.

What I claim as new. and desire to secure by Letters Patent is: p

1. Ina controller for a motor driven rotary device, in combination, control means operable automatically for periodically reversing the drivin motor and accelerating the same after eac reversal thereof, means to effect quick stopping of the motor irrespective of the speed of the latter or the rotary position of Saiddevice, said means ass through reincluding manually controlled electromechanical braking means and means operable simultaneously therewith to provide a dynamic braking efiect upon the motor, and control means operable upon initial stoping of the motor to thereafter limit t e atter to substantially constant slow speed unidirectional operation, said last mentioned means including a single manually operable switch adapted to control starting and stopping of said motor.

2. In a controller for motor operated rotary devices, the combination with means providing automatic cyclic control of operation of the device, said control including periodic reversal of rotation of the device,

' means thereafter operable at will to limit said device to unidirectional relatively slow speed operation for inching, said last mentioned means comprising a single push button switch normally biased to open position and adapted upon release thereof to render effective the aforementioned control means for quick stopping.

3. In a controller for a motor driven rotary device, in combination, control means operable automatically for periodically reversing the driving motor and accelerating the same after each reversal thereof, said means including a control drum and a continuously operable pilot motor therefor,

means to interrupt the line connections of the motor and to effect quick stopping of the latter irrespective of the speed or direction of rotation thereof or the rotary position of said device, said means-including electromechanical braking means and means operable simultaneously therewith to provide a dynamic braking effect upon the motor, and means operable upon initial stopping of the motor to thereafter render said control drum ineffective and to limit said motor to substantially constant slow speed unidirectional operation, said means for providing a dynamic braking effect and said means for providing a substantially constant slow speed including in common a resistance connected across the armature terminals of the motor.

4. In a controller for a motor driven rotary device, in combination, control means operable automatically for periodically reversing the driving motor and accelerating the same after each reversal thereof, said means including a control drum and a continuously operable pilot motor therefor, means to interrupt the line connections of the motor and to effect quick stopping of the latter irrespective of the speed of direction of rotationthereof or the rotary position of said device, said means including electromechanical braking means and means operable simultaneously therewith to provide a dynamic braking effect upon the motor, and means operable upon initial stopping of the motor to thereafter render said control drum ineffective and to limit said motor to substantially constant slow speed unidirectional operation, said last men tioned means including a single manually operable switch adapted to control starting and stopping of said motor, said means for providing a dynamic braking eifect and said means for providing a substantially constant slow speed including in common a resistance connected across the armature terminals of the motor.

In Witness whereof, I have hereunto subscribed my name.

RALPH G. LOCKETT. 

